there is a harmony section on the selection dial, you can use the dial to choose harmony octave up, or haromny octave down. Can't use both at the same time though. I think it is the first LED on the upper left hand column of the selection bank. To play octave up mixed signal toe down/octave down heel down. there are dedicated wet and dry out-puts. If you have two amps you can blend your sounds of wet and dry signals by way of the amp volume controls. If you have enough equipment you can alot of things with this pedal. the pedal does have a slight digital sound to it, but over all it is of the quality I have come to expect from Digi-Tech. I did have to re-calibrate my pedal after it had set in my closet floor for so long. Man these things can sound really bad if not calibrated, It will sound ultra-out-of-tune. to calibrate: unplug power supply, hold down activation switch while plugging power supply back into the wall. You should then see Flashing LED's, so far so good, release activation switch, put foot control to full on / toe down, move to toe up, and back. then step on activation switch. the end this all I can say about the Whammy. I have spilled guts. hope this solves all Whammy questions.